Two-piece chair

ABSTRACT

The specification discloses a two-piece chair comprising two elements of essentially obtuse angular shape, one element providing a back-rest and forward leg support and the other providing a seat and rear leg support of the chair. The elements are assembled by inserting the one end of the seat element through spaced side members of the back-rest element in intersecting relation. The seat has a rounded inner edge, the center of curvature of which coincides with the center of curvature of a rounded surface on the back-rest element, and is spaced parallel relation to the rounded inner edge is a rounded ridge which engages the back of the back-rest element to interlock the two elements. The chair elements may be cast or molded of plastic material or metal, or fabricated of wood.

United States Patent [191 Skinner [45] Jan. 21, 1975 TWO-PIECE CHAIR [75] Inventor: Harvey G. Skinner, Ligonier, Pa.

[22] Filed: July 2, 1973 211 Appl.No.:375,495

Primary Examiner-Paul R. Gilliam Attorney, Agent, or FirmBuell, Blenko and Ziesenheim [57] ABSTRACT The specification discloses a two-piece chair comprising two elements of essentially obtuse angular shape, one element providing a back-rest and forward leg support and the other providing a seat and rear leg support of the chair. The elements are assembled by inserting the one end of the seat element through spaced side members of the back-rest element in intersecting relation. The seat has a rounded inner edge, the center of curvature of which coincides with the center of curvature of a rounded surface on the backrest element, and is spaced parallel relation to the rounded inner edge is a rounded ridge which engages the back of the back-rest element to interlock the two elements. The chair elements may be cast or molded of plastic material or metal, or fabricated of wood.

5 Claims, 9 Drawing Figures PATENIED 1975 3,861,746

sum 2 or 2 iqlf Q F 9- TWO-PIECE CHAIR This invention relates to chairs of the collapsible or folding type and particularly to such chairs consisting of a minimum number of parts, such as two, which may be readily assembled and disassembled Chairs of the collapsible or folding type in a variety of different designs have been known and in use for many years. U.S. Pat. Nos. 763,490 (A. J. .lackley) and 1,715,118 (A.B. Clark) (A. B. typical of early collapsible chair designs. These designs are made of wood and require a large number of parts to be assembled, as by nails or screws. More recently, simpler designs using a minimum number of wooden parts, have been proposed, in which one element intersects another and the two interlock in assembled condition without additional securing means'to hold the parts in assembled condition. Examples of thelatter are shown in U.S. Pat. Nos. 1,949,951 (J. M. Bozarth), 2,914,117 (C. E. Un derwood) and 3,301,596 (E. A. Eos).

Other chair designs are known in which a minimal number of parts, of molded sheet material such as plywood or plastic, are adapted to be readily assembled and disassembled without requiring supplementary securing means to hold the parts in assembled condition and which must be removed for disassembly, such as shown in U.S. Pat. Nos. 2,439,322 (H. V. Thaden) and 2,881,824 (E. Herrman). 1n U.S. Pat. No. 2,439,322 the legs and seat of the chair are integrally formed of molded plywood, while the back rest portion is formed in L-shape and inserted through a slot in the seat in a manner such that the pressure of the sitter on the backrestportion is supported on the underside of the seat of the chair.

It is an object of my invention to provide a novel design of chair requiring only twov elements which intersect on a pivotal axis, such that the weight of the sitter tends to assist in maintaining the elements in interlocked relation, while reverse rotation returns the elements to a nested position. More specifically, I provide a two-piece chair having one element which serves as the back-rest portion and provides a front leg support and another element which serves as the seat portion and provides also the rear leg support. The seat element is arranged so as to fit in intersecting relation between two spaced side members of the back-rest element and is provided with an inner rounded edge that seats in a conforming circular recess in the back-rest element so that the centers of curvature of the rounded edge and of the recess coincide and provide a pivotal axis.

1 futher provide on the seat portion in spaced and substantially parallel relation to the rounded inner edge of the seat element a rounded ridge that engages the back of the back-rest portion and with the aid of the weight of the sitter interlocks the two elements tightly against separation. Reverse rotation of the elements on the pivotal axis returns them to a folded or nested positron.

A preferred form of the invention will be hereinafter more specifically described in connection with the accompanying drawings, wherein:

FIG. 1 is a view showing the assembled chair;

FIGS. 2 and 3 are views respectively showing the back-rest element and the seat element individually and disassembled;

F168. 4, 5 and 6 are elevational, profile and plan views, respectively, of the back-rest element alone; and

FIGS. 7, 8, and 9 are plan, elevational and profile views, respectively, of the seat element alone.

Referring to the drawings FIGS. 1, 2 and 3, the chair 10 comprises but two constituent elements namely a back-rest element 11 and a seat element 12. As more specifically shown in FIGS. 4, 5 and 6, the back-rest element 11 is of integral construction and may be made of metal, wood ormolded plastic material. Back-rest element 11 is of essentially obtuse angular shape, having oppositely extending portions. One portion. of substantially rectangular area and substantial thickness, constitutes the back 13 of the chair. The other portion comprises two spaced side members 14 and 14', connected by transverse slats 15 and 16. The side members 14 and 14 extend substantially horizontally from the intersection with the back 13 to provide a support for the seat element, as hereafter more fully described, and then sharply downwardly at an angle to provide the front leg support of the chair. As will be seen in FIG. 5, the back 13 is provided with a slightly spherical surface which may be plain in appearance or have a textured surface. As shown particularly in FIG. 5, the back 13 is illustratively shown as tapering in thickness from the base to the top edge. Similarly, the side members 14 and 14' are tapered in width, the horizontal section having upper and lower edges divergent by approximately 5 while the edges of the leg sections taper in width to the extent of 10". Also as shown in FIG. 5, the leg portion of the side members 14 and 14' is approximately at an angle of 60 percent to the horizontal in the assembled position of the chair.

As shown in FIGS. 7, 8 and 9, the seat element 12 is of obtuse angular shape, having divergently extending portions, one of which constitutes a seat 17 of rectangular shape and substantial thickness and the other of which comprises two side members 18 and 18 con nected by a transverse slat 19. The seat is preferably formed with a slightly spherical seating surface which may be textured if desired. Adjacent the intersection of the divergent portions of seat element 12 the seat 17 reduces somewhat in width at 20 to join the side members 18 and 18'. The inner edge of the wide portion of seat 17 is rounded, the radius of curvature corresponding to the radius of curvature at the base 21 of the back 13 by which the back 13 is joined to the side members 14 and 14'. Formed at the intersection of the two portions of seat element 12 is a rounded ridge 22 which is substantially parallel and in spaced relation tothe inner rounded edge of seat 17. The side members 18, 18' are preferably tapered in width as shown and occupy a position of 22 to 30 with the horizontal when the ele-- ments 11 and 12 are assembled together.

To assemble the chair, the side arms 18, 18' of the seat element 12 are inserted between the side arms l4, 14' of the back-rest element 11 and the rounded ridge 22 is depressed slightly to move past the back 13. The inner rounded edge of the seat 17 is thus seated against the curved surface of side arms l4, 14 at the base of the back and the seat 17 is then rotated down to seated position on the side arms 14, 14 of the back-rest element 11. In the assembled position of the elements 11 and 12 shown in FIG. 1, the elements are interlocked by the rounded ridge 22 against separation. Moreover, due to the provided connection between the elements, the weight of the sitter applied to the seat 17 further serves to maintain the interlocked relation of the elements.

When the chair is not in use, it may be collapsed or folded into more compact closed relation simply by reversely rotating the seat 17 toward the back 13 until the side arms l8, l8 engage the side arms l4, 14.

The embodiment of the invention illustratively shown in FIGS. 1, 2 and 3 is preferably made of plastic material, such as polyethylene, which may be blown or cast into the desired configuration. However, the chair may also be cast or fabricated of light-weight metal, such as aluminum. Also, if desired the elements of the chair may be fabricated of wood.

It will be apparent that modifications may be made in the chair, as shown and described herein, within the terms of the following claims.

l claim:

1. A two-piece chair comprising a back-rest element and a seat element adaptedfor interfitting engagement to form a chair, wherein the improvement resides in providing a back-rest element having two distinct portions fixed together, one of said portions being a planar portion of substantial thickness and providing a backrest and the other of said portions being of bell crank shape comprising a pair of parallel spaced side members fixed at one end to an end of said planar portion and at least one transverse member connecting said side members, said side members providing front-leg support for the chair, said seat element having two oppositely extending sections disposed divergently at an obtuse angle to each other in bell crank form, one section being of substantial thickness and constituting the seat of the chair, and the other section comprising a pair of parallel spaced side members providing rear leg support for the chair, said rear leg side members being adapted to be inserted between the spaced side members of the back-rest element with the seat section of the seat element resting on the spaced side members of the back-rest element and being fulcrumed against said end of the planar portion of the back rest element at its juncture with the bell crank portion of said back-rest element.

2. A two-piece chair according to claim 1, wherein each of said elements is integrally molded.

3. A two-piece chair according to claim 1, wherein the inner edge of the seat section is rounded and has a radius of curvature corresponding to that of a curve at the intersection between the back-rest and side members of the back-rest element, said rounded inner edge having its center of curvature coinciding with the center of curvature of said curve when said elements are assembled as a chair.

4. A two-piece chair according to claim 3, wherein said coinciding centers of curvature form a pivotal axis between the seat elements on which said elements may be rotated between open and closed positions relative to each other.

5. A two-piece chair according to claim 3, wherein said seat element has formed externally at the interseetion of the oppositely extending sections thereof a rounded ridge which engages the rear surface of the back-rest element to lock said elements together in an open position.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3,861,746 DATED January 21, 1975 INVENTOR(S) I HARVEY G. SKINNER It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below: I

In the References Cited, under the heading UNITED STATES PATENTS, "2,752,532" should read -3,752,532 and the name of the inventor shoul read -Yarus-, not "Yarns".

In the Abstract, line 11, "is" should read --in-.

Column 1, line 10, after (A.B. Clark) delete "(A. B." and insert --are.

Column 2, line 66, "provided" should read pivoted-.

Signed and sealed this 20th day of May 1975.

(SEAL) Attest:

C. MARSHALL DANN RUTH C. MASON Commissioner of Patents Attesting Officer and Trademarks 

1. A two-piece chair comprising a back-rest element and a seat element adapted for interfitting engagement to form a chair, wherein the improvement resides in providing a back-rest element having two distinct portions fixed together, one of said portions being a planar portion of substantial thickness and providing a back-rest and the other of said portions being of bell crank shape comprising a pair of parallel spaced side members fixed at one end to an end of said planar portion and at least one transverse member connecting said side members, said side members providing front-leg support for the chair, said seat element having two oppositely extending sections disposed divergently at an obtuse angle to each other in bell crank form, one section being of substantial thickness and constituting the seat of the chair, and the other section comprising a pair of parallel spaced side members providing rear leg support for the chair, said rear leg side members being adapted to be inserted between the spaced side members of the back-rest element with the seat section of the seat element resting on the spaced side members of the backrest element and being fulcrumed against said end of the planar portion of the back rest element at its juncture with the bell crank portion of said back-rest element.
 2. A two-piece chair according to claim 1, wherein each of said elements is integrally molded.
 3. A two-piece chair according to claim 1, wherein the inner edge of the seat section is rounded and has a radius of curvature corresponding to that of a curve at the intersection between the back-rest and side members of the back-rest element, said rounded inner edge having its center of curvature coinciding with the center of curvature of said curve when said elements are assembled as a chair.
 4. A two-piece chair according to claim 3, wherein said coinciding centers of curvature form a pivotal axis between the seat elements on which said elements may be rotated between open and closed positions relative to each other.
 5. A two-piece chair according to claim 3, wherein said seat element has formed externally at the intersection of the oppositely extending sections thereof a rounded ridge which engages the rear surface of the back-rest element to lock said elements together in an open position. 